Grapefruit for Fat Loss

Enhanced Metabolism

8pt;">Grapefruit may play a minor role in weight loss, but doesn’t quite live up to its fat-burning legend.

By Syrio (Own work) [CC BY-SA 4.0], via Wikimedia CommonsA relative newcomer to the citrus family, the grapefruit is widely cherished as a daytime snack for its elegantly tart, and yet sweet, flavor. Numerous anecdotal reports throughout history have cited the fruit as a fat burner, yet research seems to indicate it offers only a minor effectiveness in that regard. Supported benefits include:

Enhanced metabolism. Grapefruits carry an abundance of the polyphenol, nootkatone, which may stimulate energy metabolism by activating AMPK.

Increased glucose uptake. It’s a stretch, but this grapefruit bio-activity may help support the balanced blood sugar that’s associated with appetite control and weight management.

Source of fiber. Grapefruit pith may serve as an excellent source of pectin fiber to help decrease appetite while increasing satiation.

Overview

“forbidden fruit,” as described in Hughes’ The Natural History of Barbados (1750), is believed to have originated in Barbados as a natural genetic cross of sweet orange and pummelo, both of which were introduced from Asia in the 17th century.

Use of grapefruit (Citrus paradisi) as a dietary measure was first introduced by William H. Hay in the 1930’s due to its ostensible, and somewhat mythical, ability to burn fat. The grapefruit diet plan, revamped as the “Hollywood diet,” was decisively popularized in the 1970’s along with dozens of other diets during the American dietary craze. Declarations to the extent of: feel fat disappear and watch your waistline shrink in virtually days, toyed with unwitting enthusiasts’ desire to unearth that coveted slim body tone with the least amount of hassle.1

Eating grapefruits supposedly triggered one’s body not only to instantly oxidize fat deposits and wash them out of the system, but reduce appetite as well. The strategy entailed consuming half a grapefruit before each meal for ten consecutive days, with meals consisting of low-carbohydrate, high-protein foods.

This concept of “10-days, 10-pounds off” offered a short-term, rapid weight loss, but at the cost of a dangerously insufficient intake of 800 calories a day. With no biochemical corroboration, however, the belief that grapefruit could serve as a catalyst to burn body fat rapidly came to a fizzle.

Research in recent years, however, points to several active ingredients found in grapefruits that play a recognizable role in lowering the BMI of obese persons:

How Grapefruit Might Help With

How Grapefruit Might Help With Fat Burning

apefruits are like nutritional dynamites that are chock-full of healthy boosts, one of which is the compound nootkatone – a central activator of the AMPK signaling pathway. The significance of this finding stems from the understanding that AMPK manages the ever-complex metabolism system of the human body.5 A pre-clinical test that had nootkatone fed to mice, displayed grapefruits’ potential interactions with obesity.

Modest weight loss and BMI reduction was noted in obese mice when fed nootkatone, and fat mass appeared to be reduced.6

Stimulation of Glucose Uptake

Stimulation of Glucose Uptakepefruits are the bioflavonoids naringin and naringenin. Their interactions with glucose metabolism presented positive implications in several studies and are proven to be efficacious for the treatment of metabolic syndrome and obesity in animals.

Naringin protected mice that were exposed to a high-fat diet through activation of AMPKα.7

Naringenin battled high cholesterol and triglyceride levels in mice and may serve as a therapeutic strategy for hyperlipidemia.8

Note that effective doses still need to be established before using these bioflavonoids for clinical trials.

Effect of Citrus Flavonoids, Naringin and Naringenin, on Metabolic Syndrome and Their Mechanisms of Action.9

Supply of Fiber

Though not qui

Supply of Fiber

of the fruit, the pith of grapefruits is known to contain substantial amounts of pectin, which provides an excellent source of dietary fiber. Doses of pectin as small as 5 grams mixed with orange juice increased satiety in healthy U.S. adults and may facilitate weight loss.10

Grapefruit Reputation

Accordin

Grapefruit Reputation

rbidden fruit” may prolong life by promoting cell growth and maturation through spermidine – found in ample quantities in grapefruits and human sperm.11 Although the role of spermidine in the enhancement of human cell growth has been reported, a direct association between grapefruits and cell growth has yet to be identified and thus far hinges primarily on hearsay. Eating a lot of grapefruit and having a lot of sex is, nevertheless, not to be discouraged.

The grapefruit has further been repeatedly recommended as a fat burner, particularly alongside diet craze resurgences in the 30’s, again in the 70’s, throughout the 90’s, and quite nearly every other year since then.

Research

Animal Research

Animal Researchrch">Research

one mouse study, was administered to obese mice at 200 mg/kg body weight in order to determine its impact on weight loss. By activating AMPK in skeletal muscle and the liver, nootkatone may aid in:

The prevention of obesity and hyperglycemia in obese mice, which had significant reductions in body weight gain, abdominal fat accumulation, and development of hyperglycemia, hyperinsulinemia, and hyperleptinemia, as well as a 21% improvement in endurance capacity.

Naringenin supplementation at 0.003, 0.006, and 0.012% in rats also demonstrated various positive upshots of eating grapefruit in another study. Through activating the PPARa transcription factor, naringenin may:

Human Research

Throughout the course of six weeks, 74 overweight or obese participants ate either one half of a Rio-Red grapefruit (whole fruit) or a randomized control diet with each meal after completing a three-week washout phase. Weight loss, waist circumference, blood pressure, and lipid content were compared.

Metabolic syndrome parameters were compared among eating one half of a fresh grapefruit (127 g), grapefruit juice (237 mL), grapefruit capsules with apple juice, or placebo capsules with apple juice before each of three meals a day for a period of twelve weeks.

Concluding measurements indicated that “half of a fresh grapefruit eaten before meals was associated with significant weight loss” in metabolic syndrome patients.15

The twelve-week study examined the effects of eating, at 127 grams each, either one half of a grapefruit, grapefruit juice, or a water preload three times a day in a total of 85 obese men and women. The analysis was preceded by a two-week caloric restriction phase.

Results demonstrated that “clinically significant weight loss can be achieved when consuming a low energy dense preload before meals.” It is important to note, however, that there were no observable differences among forms of the preload – be they whole grapefruit, grapefruit juice, or water.16

Chemical synergy. Various polyphenols found in grapefruits display synergy with both caffeine and anthocyanins (the blue-red pigment ripe in berries) in Phosphodiesterase (PDE) inhibition. SINETROL – a compound combining all three – uses the interaction of its substances to inhibit cAMP-PDE and thus decrease BMI and prevent obesity. A twelve-week investigation found that obese patients with SINETROL in their diet had average BMI reductions of 2.2 ± 0.9 points.17

Grapefruit Dosage for Fat Burning

Grapefruit, like most everyday pr

Grapefruit Dosage for Fat Burning

uit. As such, specific serving sizes are difficult to identify to a tee. The most common dosages used:

127 grams of grapefruit three times a day

Either as whole fruit (one half of a grapefruit), juice, or powdered as a capsule, each providing near identical quantities of essential bioflavonoids and aromatics

Additional components of the fruit may be ingested to positive effect with no known side effects: candied or juiced pith (5 g), which supplies pectin; seed extract concoction (150 mg) with prebiotic effects.

Grapefruit supplements:

Grapefruit as a powdered supplement can be found in 500 mg capsules, equivalent to one half of a fresh grapefruit.

Grapefruit pectin in 5 g doses as a candied fruit or in servings of 3 g when taken as a capsule provides a single gram of both dietary and soluble fiber.

Grapefruit seed extracts supply between 100-200 mg and may be taken in servings of 10-15 liquid drops in water three times daily.

Side Effects

The general consensus maintains that grapefruit is a healt

Side Effects

n side effects when consumed at the recommended amount of 127 grams.

Forbidden fruit. So do we still consider grapefruit a “forbidden fruit?” Perhaps our stand on nutritional values varies based on social dictates. One study suggested that “exposure to media information on grapefruit-medicine interaction does have a tendency to result in reduced consumption.”18 Or perhaps the name is warranted, considering the plethora of contraindications it presents with medicines that have CYP3A4 interactions, with potential complications in the heart, GI tract, kidney, and liver.19

Available Forms of Grapefruit

Available Forms of Grapefruit

Whole Fruit. Frequently eaten in halves with added sugar either as a cold breakfast or as a warm evening snack. The same quantity may also be pulverized and taken as a capsule.

Juice. Most often taken as standalone grapefruit juice but is known to be mixed with other substances for taste.

Extract. Alcohol decoction of grapefruit seeds has been used in studies showing nutritional advantages. Check out other types of extracts.

Supplements in Review Recommendation

Supplements in Review Recommendation before meals.

Grapefruit is not a direct fat burner, but recommended as a dietary supplement. Although not proven to directly burn fat, grapefruit is recommended as a dietary aid that supports weight loss and stimulates healthy living. Its cardiovascular benefits should not be easily overlooked.

Take 127 grams of grapefruit (as whole fruit or juice) before meals. The citrus not only tastes great, but may also contribute to mild weight loss when taken as a meal precursor.